Diphenyl-Furanones and Diphenyl-Oxopyrrole Derivatives: From Analytical Reagents for Amino Groups to New Fluorochromes for Cytochemical Staining of Chromatin DNA and Chromosomes: Proposal for Intercalative Binding and Fluorescence Mechanism
, Silvina A. Romero 1,3, Marcelo N. Felix-Pozzi 4 and Alfonso Blázquez-Castro 5Round 1
Reviewer 1 Report
This is a fascinating look at possible new tools for investigating amino groups in situ. Though speculative at times, these are flagged up as such. The study places the new finding in context in a very thorough way.
This was overall an OK manuscript, and the only quibble is that occasionally the language is unclear to the point that the intended meaning was unknown. Below are three examples which caught my eye:
Line 75 - "when not at all".
Line 237 - "appearing the two fluorochromes".
Line 259 - "or not at all".
Whilst none of these obscurities derails the basic argument, if the authors had a native English speaker read through the manuscript this would be an even better paper.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
Stockert et al. colorants-2241840
In this manuscript, the authors report binding and fluorescence properties of diaryl-furanone derivatives on DNA and chromosomes. Binding selectivity and fluorescence mechanisms have been investigated in this work by experiments or theoretical calculations.
Comments:
(1) Characterizations such as NMR and MS for diPOPy-B, diPOPy-G and Bis- diPOPy-sp should be provided in the SI or in the experimental section.
(2) “The” is redundant from line 41.
(3) Counter ions in Fig 2 should be provided.
(4) The fl enhancement by adding glycerol in water may result more from the change in solvent dielectrics than viscosity changes.
(5) Data for fluorescence images from diPOPy-B and diPOPy-G stained material are missing.
(6) Please show molecular structures for Fig 7 beside the images as it’s very hard to read or visualize.
(7) Line 232, the authors should be careful explaining the origins of large Stokes shift.
(8) Paragraph beginning on line 330 is duplicated.
In sum, this work needs to be revised before it can be recommended for publication in Colorants.
Author Response
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Reviewer 3 Report
In this work, three furanone derivatives (diPOPy-B, diPOPy-G and Bis-diPOPy-Sp) were synthesized that emitted bright and selective blue-green fluorescence on DNA substrates. The structures with planar skeletons, the fluorescence mechanism, and the intercalative binding mechanism into AT-rich chromosome regions was proposed.
In this work, new fluorescent furanone derivatives (diPOPy-B, diPOPy-G and Bis-diPOPy-Sp) were prepared. The fluorescence and the intercalative binding mechanism were proposed and proved by theoretical and experimental results.
The topic is about fluorescent dyes that can bind selectively to chromatin DNA, which is relevant in the field. The intercalative binding mechanism was proposed for the fluorescent dyes into the AT-rich chromosome regions, which provides both prospects in mechanism explanation and practical application in pharmacological value.
In this work, the intercalative binding and fluorescence mechanism of the synthesized diPOPy derivatives with chromatin DNA were proposed and discussed, which was not investigated in the published literatures.
The following comments should be considered regarding the improvements.
1) Why the fluorescence intensity of diPOPy-B was dependent on the viscosity and/or dielectric features of the solvent?
2) The authors claimed that the molecular orbitals (HOMO-0 and LUMO+0, respectively) were well separated. However, from figure 7B, the orbitals were overlapped rather than separated. For the statement “the strongly red-shifted emission wavelength”, the control molecule should be illustrated.
3) Is it possible to characterize the structure of the “inner-salt” (Figure 10) of the model molecule by NMR characterization?
The conclusions were obtained based on the results and discussion in the manuscript and the references are appropriate.
Lastly, Figures 11 and 12 are not absolutely necessary as they are the reported results in the literatures.
Author Response
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Round 2
Reviewer 2 Report
The revised manuscript is now recommended for publication in colorants.
Author Response
Thank you.
